WADA is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-03-27. Numbers and descriptions here follow the published literature rather than marketing material.
Anti-doping laboratories identify GW501516 and related metabolites using liquid chromatography coupled with tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be analyzed. The method targets the parent compound and phase I and phase II metabolites, which extend the detection window. Because the substance is prohibited at all times, athletes can be tested outside competition. Detection limits and windows depend on the assay, sample type, and individual metabolism.
Cardarine is frequently described as a fat-burning or endurance-enhancing supplement, but these claims exceed the available evidence. The compound is not a hormone, steroid, or selective androgen receptor modulator. Research articles discuss it as a tool compound for studying PPARδ biology, while anti-doping literature focuses on its abuse and detection. Quality of unapproved products is uncertain, and independent analyses have found impurities or incorrect labeling. Open questions include whether human cancer risk resembles that seen in rodents and how often non-athletes use the substance.
Safety discussions about cardarine frequently cite rodent carcinogenicity findings reported in the 2000s. In those studies, treated animals developed tumors at multiple sites, leading sponsors to discontinue clinical development. The relevance of these findings to humans has not been resolved, but they are a major reason the compound is not approved. Current literature emphasizes uncertainty about long-term effects and the risks of unregulated use. Regulators and health agencies have not established a safe human exposure level.
Cardarine is a synthetic compound also known as GW501516, GW-501516, and sometimes endurobol. It was developed as a selective agonist of peroxisome proliferator-activated receptor delta, a nuclear receptor involved in fatty acid oxidation and energy metabolism. The compound was studied in preclinical models for metabolic and cardiovascular conditions, but it did not become a marketed human medicine. In regulatory and anti-doping contexts, it is treated as a prohibited substance rather than a licensed medicine.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Prohibited in sport; not approved as medicine | Listed by WADA at all times. |
| Common synonyms | GW501516, GW-501516, endurobol | Cardarine is a colloquial name. |
| Typical analytical method | LC-MS/MS | Detects parent compound and metabolites. |
| Common test matrix | Urine | Blood and dried blood spots also possible. |
| Legal classification | Varies by country | Often treated as unapproved drug or research chemical. |
GW501516 acts on PPARδ, a nuclear receptor that helps regulate fatty acid oxidation and energy homeostasis. In animal studies, activation of this receptor was associated with increased endurance and changes in lipid metabolism. Human trials examined effects on blood lipids and other metabolic markers, but the compound did not advance to approval. Rodent studies later reported tumors in multiple tissues at doses used in those experiments. Whether those findings translate to human risk remains uncertain, and the clinical relevance of the animal data is still debated.
Regulatory bodies treat GW501516 as a prohibited substance in competitive sport. The World Anti-Doping Agency added it to the prohibited list, and it falls under classes covering metabolic modulators and hormone-related agents. It is not approved by drug regulators for human use, and it is not a lawful dietary supplement. Products sold under the cardarine name may contain unlisted ingredients or different compounds. Because no approved product exists, quality and identity are not guaranteed by pharmaceutical manufacturing standards.
Cardarine is prohibited in competitive sport under the World Anti-Doping Agency code, where it is classified as a metabolic modulator. It is not approved as a prescription medicine in the United States, European Union, or other major markets. Regulatory action has focused on its presence in sports and in products marketed as research chemicals. Because it has no accepted medical indication, supply is often unregulated. This status creates legal and safety uncertainties for anyone who encounters the substance.
Anti-doping laboratories detect GW501516 and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be used in some programs. Detection depends on factors such as dose, timing, metabolism, and the sensitivity of the assay. Published methods describe limits of detection in the low nanogram per milliliter range for related compounds. Exact detection windows are not fixed for all situations and remain an area of ongoing study.
Cardarine is a common name for GW501516, also GW-1516, a synthetic compound developed as a peroxisome proliferator-activated receptor delta (PPARδ) agonist. It belongs to a class of agents that modulate gene transcription related to lipid and energy metabolism. The compound was studied in preclinical and early clinical research for metabolic and cardiovascular conditions, but it did not progress to approved therapeutic use. Its name appears in fitness and sports contexts despite not being approved as a drug.
PPARδ is a nuclear receptor that influences transcription of genes involved in fatty acid oxidation, lipid transport, and energy homeostasis. GW501516 binds and activates this receptor with high selectivity relative to PPARα and PPARγ in laboratory assays. Activation alters expression of target genes in skeletal muscle, liver, and adipose tissue in animal models. The exact clinical consequences of these changes in humans remain incompletely characterized, and observed effects in animals do not establish therapeutic benefit or safety.
Published studies have examined GW501516 in animal models of obesity, insulin resistance, and exercise endurance. Early human trials reportedly ended, and development was discontinued after preclinical findings raised concerns about cancer in some rodent studies. Regulatory agencies have not approved cardarine for any medical use. Its availability through non-pharmaceutical channels raises questions about identity, purity, and legal status that are separate from its laboratory pharmacology. Those questions are often addressed through analytical testing rather than assumptions about product labels.
Doses of naltrexone of 25 to 150 mg/day have been found to produce significant increases in levels of β-endorphin, cortisol, and LH, equivocal changes in levels of prolactin and testosterone, and no significant changes in levels of adrenocorticotrophic hormone (ACTH) or follicle-stimulating hormone (FSH). Naltrexone influences the hypothalamic–pituitary–adrenal axis (HPA axis) probably through interference with opioid receptor signaling by endorphins. Blockade of MORs is thought to be the mechanism of action of naltrexone in the management of opioid dependence—it reversibly blocks or attenuates the effects of opioids. It is also thought to be involved in the effectiveness of naltrexone in alcohol dependence by reducing the euphoric effects of alcohol. The role of KOR modulation by naltrexone in its effectiveness for alcohol dependence is unclear but this action may also be involved based on theory and animal studies.
== Carbamino compounds in blood == The concentration of carbamate (HbCO2) was estimated in oxygenated and deoxygenated red blood cells of adult and fetal humans. The estimation was carried out at a constant pressure of carbon dioxide (PCO2 = 40 mm Hg) and varied pH levels of the serum. The bicarbonate concentration in the red cells was calculated using the Donnan ratio for chloride and bicarbonate ions. Based on this figure, the carbamate concentration was determined by subtracting the bicarbonate concentration and dissolved CO2 from the total CO2 concentration. Deoxygenated fetal red cells contain more HbCO2 than deoxygenated adult red cells at a given pH value in the red cell. Upon oxygenation, HbCO2 decreased in both types of erythrocytes to values lower than in deoxygenated cells, at a constant pH. The fraction of 'oxylabile carbamate' (-ΔHbCO2/ΔHbO2) at a red cell pH of 7·2 and a PCO2 of 40 mm Hg is 0·117 in fetal and 0·081 in adult erythrocytes. The apparent carbamate equilibrium constants (K'c and K'z) were calculated from the fraction of moles carbamate formed per Hb monomer (moles CO2/mole Hbi). These constants can be used to estimate the carbamate concentration in normal adult and fetal blood. In adult red cells, the first apparent dissociation constant of carbonic acid is significantly higher in oxygenated (-log10K'1 = pK'1 = 6·10) than in deoxygenated (pK'1 = 6·12) red cells, whereas in fetal red cells, the difference is smaller and statistically not significant.
== Science and technology == MSI Barcode, a continuous numeric barcode symbology Microsatellite instability, an abnormality of DNA Mass spectrometry imaging, a technique used in mass spectrometry Mass sociogenic illness, the rapid spread of physical symptoms of illness among the members of a group with no physical or infectious cause Magnetic source imaging, magnetoencephalography combined with magnetic resonance imaging Multispectral imaging, the capture of multiple, specific wavelengths in the electromagnetic spectrum Musculoskeletal injury, damage of muscular or skeletal systems which is usually due to a strenuous activity
== In popular culture == The 1960 British war film Sink the Bismarck! discusses the strategic importance of the GIUK gap during World War II naval operations in the Atlantic theatre, and depicts the Battle of the Denmark Strait between British and German forces. It is based on the novel The Last Nine Days of the Bismarck by C. S. Forester. The GIUK line is mentioned in the film The Bedford Incident. In Tom Clancy's first novel, The Hunt for Red October, the line was used to detect Soviet submarines entering the North Atlantic in pursuit of the rogue Typhoon-class submarine Red October, whose officers were defecting to the United States with clandestine stealth technology. The event causes significant political and military tension between the United States and the Soviet Union. The film adaptation also references the gap, with National Security Advisor Jeffrey Pelt (played by Richard Jordan) saying to the Soviet ambassador "Your aircraft have dropped enough sonar buoys so that a man could walk from Greenland to Iceland to Scotland without getting his feet wet." In Clancy's second novel, Red Storm Rising, the line is featured more prominently after a war breaks out between NATO and the Warsaw Pact. The Soviet Union launches a surprise attack on the NATO airbase NAS Keflavik and invades Iceland. This causes the line to be destroyed, creating a gap in NATO's surveillance and allowing the Soviet Navy to enter the North Atlantic.
=== Blood testing === Allergy blood testing, typically measuring allergen-specific IgE, is a quick test that can be ordered by a qualified healthcare professional. Unlike skin-prick testing, it is not affected by antihistamines and may be used when skin testing is impractical, such as in people with extensive eczema or other skin disease, in pregnancy, or when there is concern about provoking symptoms. It can be performed in adults and children, including infants, although results must be interpreted together with the clinical history because sensitisation does not always mean clinical allergy. An allergy blood test is available through most laboratories. A sample of the patient's blood is sent to a laboratory for analysis, and the results are sent back a few days later. Multiple allergens can be detected with a single blood sample. Allergy blood tests are very safe because the person is not exposed to any allergens during the testing procedure. After the onset of anaphylaxis or a severe allergic reaction, guidelines recommend that emergency departments obtain a time-sensitive blood test to measure tryptase levels and assess for mast cells activation. The test measures the concentration of specific IgE antibodies in the blood. Quantitative IgE test results increase the possibility of ranking how different substances may affect symptoms. A rule of thumb is that the higher the IgE antibody value, the greater the likelihood of symptoms. Allergens found at low levels that today do not result in symptoms cannot predict future symptom development.
Sources: en.wikipedia.org
AAA proteins are divided into seven basic clades, based on secondary structure elements included within or near the core AAA fold: clamp loader, initiator, classic, superfamily III helicase, HCLR, H2-insert, and PS-II insert. AAA ATPases assemble into oligomeric assemblies (often homo-hexamers) that form a ring-shaped structure with a central pore. These proteins produce a molecular motor that couples ATP binding and hydrolysis to changes in conformational states that can be propagated through the assembly in order to act upon a target substrate, either translocating or remodelling the substrate. The central pore may be involved in substrate processing. In the hexameric configuration, the ATP-binding site is positioned at the interface between the subunits. Upon ATP binding and hydrolysis, AAA enzymes undergo conformational changes in the AAA-domains as well as in the N-domains. These motions can be transmitted to substrate protein.
When an 235U atom captures a neutron, it is converted to an excited state of 236U. About 85.5% of the excited 236U nuclei undergo fission, but the remainder decay to the ground state of 236U by emitting gamma radiation. Further neutron capture forms 237U which has a half-life of 7 days and quickly decays to 237Np through beta decay. During beta decay, the excited 237U emits an electron, while the atomic weak interaction converts a neutron to a proton, thus creating 237Np.
Angiotensin II, endothelin-1, or phenylepinephrine cause HSP70 overexpression, which activates several molecular pathways, resulting in increased production of ROS, CRP, IL-10, TNF-alpha, and IL-6 These inflammatory signals interfere with the antioxidant machinery and results in rapid disease progression. HSP70 expression increases after the coronary bypass surgery. Exercise has a positive and protective impact on cardiovascular disorders and stimulates the increased production of chaperone protein, which is cardioprotective.
=== Current squad === The following players were called up for the friendly matches against Mexico, Paraguay and Peru on 26 September and 2 and 6 October 2026, respectively. Caps and goals updated as of 26 September 2026, after the match against Mexico.
Sources: en.wikipedia.org
Legal status varies by country. It is not approved as a medicine, and it is prohibited in sport. Some jurisdictions restrict import, sale, or possession.
Laboratories use liquid chromatography-tandem mass spectrometry to detect GW501516 and its metabolites. Urine is commonly tested, and testing can occur in and out of competition.
No, cardarine is not a SARM. It is a PPARδ agonist, which acts on a different receptor. The two classes are often confused in online discussions.
Cardarine is an investigational synthetic compound that acts as a PPARδ agonist. It is also known as GW501516 and has been studied mainly in preclinical research. It is not an approved medicine.